Expansive reamer



April 2z, 1941.

2 Sheets-Sheet l A J. GRANT EXPANS I VE BEAMER Filed Feb. 20, 1939 April22, 1941.

y J. GRANT 2,238,998V

EXPANS I VE BEAMER Filed Feb. 20, 1939 2 Sheets-Sheet 2 Patented Apr.22, 1941 UNITED STATES PATENT oFFicEl EXPANSIVE REMER John Grant, LosAngeles, Calif.

Application February 20, 1939, Serial No. 25'7i426' 3 Claims. (Cl.Z55-76) This invention relates to expansive well reamers; and it isamong the objects of the invention to produce an effective and ruggedreamer of large expansive capacity; to produce such a reamer in suchform and of such strength and ruggedness that it can utilize, and willwithstand the forces resultant from the use of, roller cutters; andfurther to produce such a reamer of large expansive capacity and cuttingefficiency, which is actuated by hydraulic pressure and in which thecutting action of the mud laden circulation fluid is minimized. It isalso an object of the invention to produce such a tool as hereinreferred to in simple and rugged form. And

there are many other objects and corresponding y accomplishments of theinvention which, together with the foregoing, will be better understoodfrom the following preliminary discussion and specific description ofillustrative forms embodying the invention.

In the past expansive well rea-ming tools using blade type cutters,sometimes known as wall scrapers, have been designed to have anexpansive capacity relatively large as compared with the more limitedexpansive capacity of the expansive reaming tools which are commonlyknown in the trade as underreamers and commonly use cutters of theroller type. These large expansive tools have commonly used expansivecutters of the blade or scraping type. They have commonly been actuatedby hydraulic pressure. But their serious limitations have been due totheir inability to utilize roller cutters with their accompanyingsuperior and dependable cutting action, to their relative weakness ofdesign particularly with relation to the thrusts and forces which wouldbe imposed upon them if roller cutters were used, and to their lack ofsimplicity and ruggedness of structure with relation to their hydraulicactuation of the cutters, and as well their tendency to have their partscut out by the abrading action of the mud laden circulating fluid. Itmay be stated as one general object of the present invention to overcomethese priorly encountered diiiiculties. Among these objects I may,without minimizing others, particularly emphasize that of providing atool using roller cutters but having large expansion. The prior bladecutters have large expansion, but they wear so quickly that they cannotbe depended upon to enlarge any substantial footage of hole in hardformation to any definitely determinable diameter. In this connectlon.the object of the invention is to attain the desired expansion in a toolutilizing roller cutters. so that the enlargement of the hole to adefinitely predetermined size can be relied In one aspect of my presentinvention, it may be regarded as an improvement upon the type ofhydraulic cutter actuation which is the subject-matter of copendingapplication Ser. No. 167,389, led October 5, 1937, by James J. Santiago.My present invention utilizes certain of the fundamental features ofstructure and function shown in said Santiago application, and furtherimproves `upon that prior structure by simplifying the interconnectionbetween the hydraulically actuated plunger and the expansively movablecutters, by making a part of the plunger directly contact the cuttersboth for purposes of their expansive movement and for forming anabutment for the cutters when expanded. And further, as compared withthe type of tool shown in said Santiago application, my presentinvention further improves the mounting of the cutters, vparticularly asto solidity and strength and ability to take the thrusts and forceswhich are developed upon roller cutters.

The invention in its various aspects will be best understood from thefollowing detailed description of certain illustrative and typical formsof expansive reamer illustrated in the accompanying drawings in whichFig. 1 is a vertical central longitudinal section of an expansive reamerillustrative ofthe invention;

Fig. 2 is a fragmentary elevation of the same;

Fig. 3 is a section taken on line 3-3 of Fig. l;

Fig. 3a is a cross section on line 3cr-3a of Fig. 1;

Fig. 4 is an enlargement of certain portions of the sectional view ofFig. 1;

Fig. 4a, is a similar view showing the parts in contracted position;

Fig. 5 is a diagrammatic perspective showing the inner end of acutterarm; l

Fig. 6 is a similar fragmentary section showing adaptation to adiffe-rent type of roller cutter, the cutter in this view being shown incontracted position; and

Fig. 'l is a section showing adaptation to another type of rollercutter.

In the drawings the tool is shown as having a hollow body IIJ adapted atits upper end for attachment to a sub, or drill stem or the like,indicated at Il. In its upper part this body Ill has a main plunger borel2 in which a plunger head reciprocates, indicated generally by thenumeral I3. Immediately below the plunger bore I 2 there extends asomewhatl smaller plunger guide bore I4, in which the depending plungerI5 reciprocates. The lower end of the guide bore I4 opens into a largerbody bore I6 which extends to a point near the lower end of the toolwhere the body carries the usual bit I'I. In the drawings this bit isshown as being integral with the body, although it need not be so.

t is preferred that a tool of this character have three cutters, andaccordingly the body is provided with three cutter-receiving slots 20,of which the lower portions 2i are of suicient width to take the rollercutters hereinafter described, and the upper portions 22 are ofnarrowerjwidth and adapted snugly to take the thicknesses of theswinging cutter arms 23. As Ashown "in the present illustrative design,`the upper ends of the lower and wider portions of slotsuZI ektendto'theline shown at 26 in Figs. 1 and 4, this line also demarking the lowerextremity of the narrow -upper slot portions 22. As shown inthe crosssections of Figs. 3 and 3a, the upper narrower slot lower ends of thenarrow body slots 22. The purpose'of this arrangement, as will becomemore clearhereinaiter, is to provide certain shouldering faces on thesurface oftheupper p art ofthat large body bore adjacent the swingingcutter'arms 23.. .In the design as here shown, the transverse Apivots.for the swinging cutter arms Y2? are mounted approm'mately at the levelof the said shoulder 2l. And this shoulder 21, in such posi- Vtionrelativeto the cutter pivots, also demarks the lowerend of'the'plungerguidenbore I4.

Each swinging cutter arm23 carriesatits outer end a roller cutter '321,of which the details and f variations will be consideredlater. At theinstant it is sufficient tonote "that, the swingingarms of .i

the present illustrative tool have been designed to take expandedpositions swung outwardly to about the 60 angle yshown for instance inFigs.

' 1 and 4, although this particular angle isfnot neci essary, and totake contracted 4positions hanging vertically downwardly in the bodyslots 20, as

' shown in '.Fig. 4a. It is thegeneral-purpose and function of the partsnow'to bedescribedto cause and allow expansive and contractive movementsof the cutter arms, and to ruggedly support the Acutter arms and cuttersagainst all the forces and thrusts which are imposed upon'them.

The plunger head I3 shown in Fig. 1 is substantially similar to thecorresponding plunger head shown in the said Santiago application, and

to it in itself I make no claim. This plunger head hasa relatively largehollow interior 35, and an upper preferably conical end 36 having two ormore narrow'entrance slots-31 through which the circulation fluid flowsdownwardly and inwardly, and in restricted high velocity str eams'intothe large plunger interior in opposed relation so that the highYvelocities are broken up by interbe used.

extension of plunger head I3, and this plunger I5 plays in the plungerguide bore I4 with a sufciently close fit to guide the plunger fairlyaccurately and to enable it to form an interior central and commonabutment for the several cutter arms, as hereinafter described.

At the same time, the plunger I5 lits bore I4 with suiiicient clearancethat fluid circulation may be maintained through the clearance ifdesired, :as hereinafter explained. In the operation of the device ltheplunger I5 moves between its lowermost position shown in Fig. 1 and itsuppermost position shown in Fig. 4a. To prevent the plunger from risingmuch beyond its uppermost position, any suitable motion limiting meansmay be used. In the present instance I have shown a stop sleeve lIdepending from the sub II and adapted to form a stop to limit the upwardmove- 'ment of -plunger head I3 to a position that corresponds to, or alittle above, the upper position of plunger I5 shown in Fig. 4a. Tolimit downward movement of the rplunger and prevent it from `moving onvdown and'locking the cutter arms in expanded positions, any suitablestop means vmay For instance in Fig. 1 stop lugs '4I are show-n on theplunger, engaging the shoulder 42 at the lower end of bore I 2.

The interior chamber 35 of plunger head I3 is continued on downwardlythrough plunger 'I5 by the plunger bore `42's. Thelower part of-thisbore is diminishedin size, as at 46 and loosely Vtakes the upperend of the circulation pipe 41 which is mounted at its lower end invbore 43`in the'lower end of the body. From bore '4.8 circulation ducts,such vas 49 and 5U, lead off to deliver circulation to bit Ilandoutwardlyjand upwardly under the cutters '30. The use of an interiorcentral-circulation pipe, as here described, ob-viates-the necessity ofcarrying circulation to the -lower `part .of the body by Vpassagesleading down through the l outer parts of the body, as is usually donein. tools vof vthe kind described here. Such circulationpassagesmaterially weaken theibody at its slotted portion The centralpipeobviatesall such weakening.

Bore 460i the plunger I5 is recessedjrat-a'to -provideanV annularchannel in which packing may :be inserted if it is desired-not to havedownward "circulation through the clearance in bore #I6-surrounding pipe'4`I. V.The'stop'sleeve '40 prevents plunger I5 from rising high enoughvtolmove out the tool is otherwise'liable to move'the plunger u up outofproper engagement.

impingement of the streams. The back pressure set up by these restrictedslots 3'I is the pressure which tends to force the plunger head I3downwardly. The plunger head-carries apacking ring 38 engaging the wallof bore I2 to-prevent leakage direct ciwntvrd Before explaining Ythedetails ofv the cutter 'mountings and abutme'ntsv I will first explainthe modes of circulationthat may beha'd. As `s'hown in thedrawingsthealower part of 'the plunger head VI3 has large Aopenings .i'fin itslwall, fso vthatV circulation Vmay pass from Ythe interiorfchamberf 35.of the 'head into the 1 bore '.I 2 belowpackin'g'.' Ifxthe'seopenings-55 are used, Ythen a part lof the circulation'passes idownthrough the annular 'clearance -around plunger I5 in Abore lidia'nd isdelivered r`at the lower -end of bore I4 directly over-theinne'rendsfofwthe cutter arms "213, :and thus 'serves as'circulation to theimmediate'vicinity o'f,orvr above, the lcutters. jI-Iowever I noteparticularly vthat the openings "V55 may be dispensedjwith,andi-the'walliftthe charriberr 35 "made solid, in `whic'hfcase therewill be no circulation around the outside of the plunger.

As is seen in the drawings, the upper end of circulation pipe 41communicates directly with the plunger lbore 45 and head chamber 35, sothat circulation from the chamber interior takes place through that pipeto the circulation ducts at the lower part of the body. Furthermore theannular clearance around pipe.41 in plunger bore 45 also communicatesdirectly. with bore 45 and head chamber 35, so that circulation may bemaintained through that clearance if desired. This circulation, if used,discharges at the lower end of plunger I near, or directly under, theinner ends of the cutter arms 23, and thus discharges in the directvicinity of the cutters.

Like the circulation around the outside of plunger I5, that around theoutside of pipe 41 may be dispensed with if desired, by insertingpacking in the channel 46a. On the other hand, if circulation ismaintained around the outside of the pipe, it may either becomparatively small or large in quantity, as the clearance is made smallor large. Either one or both, or neither, of the above circulations maybe used; and if used they may be made to be of any desired relativevolumes by constricting or enlarging the clearances.

In any case, regardless of which circulation passages are used, it willbe seen that all of them are fed from the large interior chamber 35 of62, Vand the walls Bl of the recesses bear closely the plunger head, andthat that chamber can only receive circulation through the restrictedports 31. These restricted ports are preferably so dimensioned thattheir total area is less than the smallest total ilow area beyond thehead chamber 35. For instance, if only the circulation pipe 41 is usedfor circulation, then the total area of ports 31 is preferably less thanthat of pipe 41, so that the highest velocities are set up at the ports'31 and substantial actuating pressure is applied to the plunger head,and also so that substantially all the cutting and wear due to highvelocity streams is localized at ports 31.

Once the high velocity streams enter the large chamber in the plungerhead, all high velocity flow ceases. From that chamber the flow, bywhatever routes it travels, is relatively slow and quiet.

Each cutter arm 23 has in its inner end a recess whose back face 6| iscylindric and of a curvature to fit the cylindric face of plunger I5.This recess is so aligned in the cutter arm that its cylindric wall isvertical when the cutter arm is in expanded position, as shown in Figs.1 and 4. The bottom 62 of recess 60 is located and shaped so as to t theconical end surface 63 of the plunger. In the expanded position of thearm the recess bottom 62 is below the swinging center of the arm onpivot pin 28, and the end portion of the plunger is somewhat relieved at64 above conical surface 53 so that the conical surface 63 may keep incontact with recess bottom 62 as the arm swings between the expandedposition of Fig. 4 and the contracted position of Fig. 4a. In thecontracted position, shown in Fig. 4a, the conical seating end of theplunger may still rest on the recess bottom 62, although not flatly.When the plunger is forced downwardly by the hydraulic action, downwardpressure of the plunger end on the recess surfaces 62 forces the cutterarms to the expanded positions of Figs. 1 and 4. In that position thelower end of the plunger seats on the recess bottoms against thecylindric surface of the plunger. By

this arrangement all the cutter arms are given mutually a solid internalbacking against the central plunger so that inward pressures on the armsare sustained. In case the lower walls of the recesses B0, at the lowerwall surfaces 62,

should break off or wear away, the previously explained stops 4l on theplunger prevent the plunger from moving on down below its properlowermost position and locking the cutter arms so that they could not beswung downward for retraction. Retraction is effected by pulling thetool up into the well casing, the arms contacting the casing shoe andbeing swung down and in. When the arms are thus swung down they raisethe plunger to its upper position.

In the expanded positions of the arms, their upper surfaces, at pointsoutside the pivot centers 28, bear upwardly against abutment surfaces 65which are located on the body at the upper ends of the body slots. Inthe particular design as here shown, where the upper surfaces of thearms are at an angle, the abutment faces 65 are likewise at that angle,so that flat seating is attained. The function of these abutmentsurfaces is to form a stop, located at one side of the pivot 28, tolimit upward swinging of the cutter arm.

The stop lugs 68, with their shouldering faces B1, form other abutmentsat the opposite sides of the pivots 28 to limit upward swinging of thecutter arms. These stops are formed on the opposite faces of the arms attheir inner ends, in such positions that their faces 51 bear outwardlyagainst the faces 16a of the bore I6 when the cutter arms are expanded.See Figs. 3 and 4. These rotational stops being located opposite to therotational stops $5, they take all or substantially all the thrustswhich are generated by forces tending to rotate the arms upwardly, andthus take the resultant shearing stresses off the pivot pin 28. Themajor forces to which the cutters and cutter arms are subjected areupward forces, inward forces and circumferential forces. The upwardforces acting on the outer ends of the cutter arms are here taken careof by the stops above described and also by the recess surfaces 6Ibearing against the central plunger. These bearing faces and stops takeoff the pivot pins shearing stresses that would otherwise be placed uponthem. The inward forces that would also otherwise have to be carried bythe pivot pins are taken by the inward bearings of the arm faces 6l onthe central plunger. Circumferential forces acting on the outer ends ofthe cutter arms are taken care of by the lateral bearing of the sidefaces of the arms against the side walls of the upper narrow portions 22of the body slots 23. The cutter arms are thus solidly supported attheir inner ends against all thrusts, and accordingly they can be madelong enough to carry roller cutters at a considerable expansiondiameter, and still carry all the thrusts to which the roller cutterslocated at such a cutting diameter are subjected in heavy service.

Various forms of roller cutters may be carried on the outer ends of thecutter arms, the particular form being dependent upon the servicerequired. Figs. 1 to 4 show roller cutters 3l! arranged on axeslongitudinal of the arms. As shown in Fig. 1, the outer end of the armmay be shaped to form a tapering pin 10, and the cylindric cutter body1| has a corresponding bore. The outer end 12 of the cutter may beconical, and provided with cutting teeth, as is the cylin- Adricsurf-ace.

The outer lend of `the cutter bears back; against an end-thrust .bearingball 13. Near the inner end, the cutter may have bearing on balls 14which, running in races 15 and 1.6 in the cutter and the bearing pin 1|,also serve to hold the cutter endwise on the pin.

In Fig. 6, a roller cutter 30a is `shown mounted on an axis pin 80 whoseaxis is at an angle to the length of the arm 23a and at right angles tothe axis of pivot pin 28. Axis pin 8D is held in arms 8l at the outerend of the cutter arm 23a. And thrust washers 82 are provided at theends ofthe roller cutter; the cutter runs on roller Y bearings 83, andthe pin 8U is secured solidly in In Fig. '1 another type of rollercutter is shown,

a crown cutter 30h, Here again the cutter rotates on an axislongitudinal of the cutter arm 23h. Ther outer end face 85 of thiscutter is frustowonical and has teeth 86. The outer part of the cutterhas a central bore 81, and the inner part of the cutter a large bore 88.This `inner large bore takes a ball race ring 89 and ball bearings 90which take both radial and end thrust. pins 9|. Between bores 88 and 81the cutter has an internal iiange 92 which surrounds a reduced portion93 `of an ,axial boss -94 integral with arm 2319. A retention screw 95has its head 95 overlying the ange 92, and the screw is looked againstloosening by the lock pin 51.

These and various other forms of roller cutters may be utilized, in factany roller cutter form that can effectively be mounted on the outer endof such arms as I describe. My invention is f not limited to anyparticular form of cutter, being characterized by its provision ofrugged and solidly mounted cutter arms' capable of giving largeexpansion regardless of the type of cutter used, but capable ofutilizing roller cutters.

I claim:

l.. In an expansive reamer, an elongate body having in its upper portiona plunger receiving bore, a plunger with an upper plunger headreciprocabie vertically in said bore, said plunger fhaving alongitudinal bore open at its lower end and the plunger head beinghollow and in cornmunication with the plunger bore, .a restricted fluidentry port in the upper end of the plunger n head, a packing surroundingAthe plunger head The race ring is held non-rotative by aeaaooe anopening through its wall below the packing, a circulation pipe mountedin the lower part of the body and entering the lower end of the plungerbore to receive fluid therefrom, the body having cutter larm receivingslots immediately below the plunger bore, and cutter arms pivoted insaid slots and adapted to take the lower end of the plunger betweenthem.

2. In an expansive reamer, an elongate tubular body havinglongitudinally extending radial cutter arm receiving slots through itswalls, swinging cutter arms in said slots mounted to swing on pivotswhich extend transversely of the body and across the slots, said armsadapted to Swing from positions longitudinal of the slots to positionsextending outwardly from the body, stop means on the body adapted toengage the arms at a point radially removed from the arm pivots andadapted to limit outward swinging of the arms, and other stop means onthe arms at the opposite side of their pivots and adapted to engage thebody to limit outward swinging of the arms, the pivoted ends of the armshaving plunger receiving recesses which recesses have side walls lyingin a cylindric formation when the arms are vexi'iended and whichrecesses also have end walls, and means in the body for swinging thearms outwardly, said means including a cylindric plunger movablelongitudinally of the body to engage its end with the said recess endwalls .and adapted to be received in the several recesses to form acentral abutment between the arms.

3. In an expansive reamer, an elongate tubular body havinglongitudinally extending radial cutter arm receiving slots through itswalls, said slots terminating at their upper ends at downwardly facingwall shoulders, swinging cutter arms ,in said slots mounted at theirupper ends to swing on pivots which extend transversely of the body andacross the slots near their upper ends., the arms adapted normally tohang downwardly from the pivots and to swing upwardly and outwardly fromthe body, each arm having a stop surface at its outer side near its topadapted .to engage a wall shoulder, each arm having a projecting stopshoulder adjacent its inner side near its top and adapted to engage theinner surface of the tubular body, the upper pivoted ends of the armshaving plunger receiving recesses which have side walls that liesubstantially vertically when the arms are swung outwardly and whichalso have bottom walls, and a downwardly movable plunger in the bodyadapted to engage its lower end with the several recess bottom walls andadapted to be received in the several recesses to form a centralabutment bey

